1. Field of the Invention
The present invention relates generally to portable coolers that can keep food and other perishables cool when away from a power source and, more particularly, to a portable cooler that can be collapsed to occupy a relatively small volume when the cooler is not in use.
2. Description of the Prior Art
Portable coolers are very useful devices for keeping food and other perishables cool when away from a source of electrical power. Often coolers are rigid structures that occupy substantially the same volume of space whether the cooler is in use or empty. For practical storage purposes, it would be desirable if a portable cooler would occupy less space when not in use than when actually in use.
The cooling medium often used for portable coolers is ice. A problem, however, associated with the use of ice is the liquid water that results from melted ice. The liquid water can penetrate into food containers if they are not provided with a water-fight seal, and very often they are not provided with such a seal. In this respect, it would be desirable if a portable cooler were provided with means for cooling stored items without using ice.
As an alternative to the use of ice for cooling in portable coolers, sealed modules containing special heat-transfer materials have been developed. Such heat-transfer materials include mixtures of glycols and water. Such glycol mixtures are referred the use of conventional water ice, it would be desired if a portable cooler employed sealed modules containing blue ice or the like.
Sealed modules containing blue ice are often placed in a home freezer compartment for a period of time, e.g. overnight, to allow the blue ice to freeze. A home freezer compartment is often used for a variety of purposes, and space therein is often very crowded. Thus, it would be desirable if a sealed module containing blue ice occupied a relatively small space in a freezer compartment.
Throughout the years, a number of innovations have been developed relating to portable coolers and collapsible containers, and the following U.S. patents are representative of some of those innovations: U.S. Pat. Nos. 2,519,960; 3,262,283; 5,035,122; 5,076,711; and 5,231,850. More specifically, U.S. Pat. No. 2,519,960 discloses a frozen food package in which blue ice is not employed.
U.S. Pat. No. 3,262,283 discloses a portable cooler that collapses for storage and that includes hollow walls in which a temperature modification medium is contained. More specifically, U.S. Pat. No. 3,262,283 discloses a non-folding floor, four walls, and a lid. The four walls are non-folding along the respective interior wall surfaces defined by the respective perimeters of the respective four walls. The non-folding walls are connected by hinges to the non-folding floor. Because of the non-folding nature of the four walls, when the device in U.S. Pat. No. 3,262,283 is collapsed for placement in a freezer, edges of the non-folding walls, which are adjacent to each other when the portable cooler is in a storage mode, are moved apart from one another, and the four non-folding walls are placed in the plane of the floor in the collapsed mode. To return the portable cooler to a storage mode, the four non-folding walls are lifted out of the plane of the floor of the device, and the edges of the four walls are placed adjacent to one another. A significant disadvantage in using the portable cooler in U.S. Pat. No. 3,262,283 is the need to essentially disassemble the device to collapse the device for placement in a freezer and the need to essentially reassemble the device for placement in the storage mode.
U.S. Pat. No. 5,035,122 discloses a portable cooler that includes non-folding walls which include a freezable gel within wall interiors.
U.S. Pat. No. 5,076,711 discloses a collapsible, two-walled container for holding fish and ice. The walls of the container, though flexible, are not disclosed as folding along the respective interior wall surfaces defined by the respective perimeters of the respective walls.
U.S. Pat. No. 5,231,850 discloses a portable cooler that includes non-folding walls which include a refrigerant within wall interiors of the cooler.
Still other features would be desirable in a collapsible cooler apparatus. As mentioned above, it would be desirable to be able to interconvert a portable cooler from a collapsed mode to a storage mode without concomitant disassembly and reassembly. As a corollary, it would be desirable to be able to convert a portable cooler from a collapsed mode to a storage mode with a simple, one-handed pulling motion. In addition, it would be desirable to convert a portable cooler from a storage mode to a collapsed mode with a simple, one-handed pushing motion.
Thus, while the foregoing body of prior art indicates it to be well known to use portable coolers which collapse for storage, the prior art described above does not teach or suggest a collapsible cooler apparatus which has the following combination of desirable features: (1) occupies less space when not in use than when actually in use; (2) provides means for cooling stored items without using water ice; (3) employs sealed modules containing blue ice or the like; (4) provides sealed module containing blue ice which occupy a relatively small space in a freezer compartment; (5) avoids the need to essentially disassemble a device to collapse the device for placement in a freezer and avoids the need to essentially reassemble the device for placement in a storage mode; (6) enables conversion of a portable cooler from a collapsed mode to a storage mode with a simple, one-handed pulling motion; and (7) enables conversion of a portable cooler from a storage mode to a collapsed mode with a simple, one-handed pushing motion. The foregoing desired characteristics are provided by the unique collapsible cooler apparatus of the present invention as will be made apparent from the following description thereof. Other advantages of the present invention over the prior art also will be rendered evident.